Hey team,
The datasheet of the UCC27524 (last paragraph of 8.3.3 - Input Stage) talks a bit about the implications of slow rise and fall times on the input of gate driver. It implies that slow slopes may cause repeated high-frequency switching on the output of the driver (sounds quite dangerous in power MOSFET applications). In the next sentence though, it mentions that the wide hysteresis "alleviates the concern over most other TTL input treshold devices". Also "If limiting the rise or fall times to the power device is the primary goal" (it is, i'm using a slow optocoupler as control), a gate resistor is recommended on the MOSFET. These statements leave me a bit confused. How will a gate resistor help with high-frequency switching on the output? How fast does my input slope need to be to avoid switching on the output? Shouldn't the hysteresis on the UCC27524 inputs solve this problem altogether?
Kind regards,
Lars